Necessary Existence breaks ground on one of the deepest questions anyone ever asks: why is there anything? The classic answer is in terms of a necessary foundation. Yet, why think that is the correct answer? Pruss and Rasmussen present an original defense of the hypothesis that there is a concrete necessary being capable of providing a foundation for the existence of things. They offer six main arguments, divided into six chapters. The first argument is an up-to-date presentation and assessment of a traditional causal-based argument from contingency. The next five arguments are new "possibility-based" arguments that make use of twentieth-century advances in modal logic. The arguments present possible pathways to an intriguing and far-reaching conclusion. The final chapter answers the most challenging objections to the existence of necessary things.